The kinetics of cracking, coking, and devolatilization of Athabasca bitumen were investigated by reacting thin films of feed material. Samples of vacuum residue (524 degreesC+), scrubber bottoms, and residue from a batch fluid coker were reacted in films of thickness 20 mum on strips of Curie-point alloy. The strips were heated to temperatures of 457, 503, and 530 degreesC in a nitrogen atmosphere using an induction furnace. After reaction, the remaining unconverted liquid was extracted from the films, the toluene-insoluble residue was weighed, and the condensed vapor and extract liquids were analyzed for microcarbon residue content (MCR) and boiling distribution by simulated distillation. The kinetics of reaction and devolatilization were consistent with a lumped kinetic model that included cracking, coke formation, and vaporization limited by equilibrium ratios and mass transfer. The kinetic model was able to reproduce the experimental data for total extractable and coke yield as a function of time, as well as the yields of residue and gas oil fractions in the vapor product and remaining in the liquid film. Even though the heavy residue fractions had equilibrium ratios of less than 0.01, 10-15 wt % of the feed appeared in the vapor product as 650 degreesC+ material. MCR content correlated well with the fraction of 650 degreesC+ material; therefore, the model predictions were consistent with the MCR content of the vapor products.